/* ========================================
   BATTLESHIP GAME - PREMIUM AUTH UI
   Theme: Modern Naval Warfare with Clean Typography
   ======================================== */

/* Global Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Body - Background with Naval Theme */
body {
    font-family: 'Be Vietnam Pro', 'Inter', 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: url('../images/backgrounds/index.png') center/cover no-repeat fixed;
    min-height: 100vh;
    position: relative;
    color: #1d3557;
}

/* Overlay for better contrast */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(10, 25, 47, 0.85) 0%, rgba(29, 53, 87, 0.75) 50%, rgba(69, 123, 157, 0.65) 100%);
    z-index: -1;
}

/* Container - Không ép chiều cao */
.container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 40px 20px;
}

/* Auth Box - Glass Effect - FIT CONTENT */
.auth-box {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 20px;
    box-shadow: 
        0 8px 32px rgba(0, 0, 0, 0.3),
        0 4px 16px rgba(69, 123, 157, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.4);
    max-width: 440px;
    width: 100%;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    animation: fadeInUp 0.6s ease-out;
}

.auth-box:hover {
    box-shadow: 
        0 12px 40px rgba(0, 0, 0, 0.35),
        0 6px 20px rgba(69, 123, 157, 0.25),
        inset 0 1px 0 rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Auth Header - Naval Theme - LOGO HERO */
.auth-header {
    text-align: center;
    padding: 44px 24px 28px;
    background: linear-gradient(135deg, rgba(10, 25, 47, 0.95) 0%, rgba(29, 53, 87, 0.9) 50%, rgba(69, 123, 157, 0.85) 100%);
    color: white;
    position: relative;
    overflow: visible;
}

.auth-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: repeating-linear-gradient(
        90deg,
        transparent,
        transparent 50px,
        rgba(255, 255, 255, 0.03) 50px,
        rgba(255, 255, 255, 0.03) 51px
    );
    z-index: 0;
}

/* Logo HERO - Phóng to hơn */
.auth-header .logo-container {
    text-align: center;
    margin-bottom: 24px;
    animation: logoHeroEntrance 1.2s ease-out;
    position: relative;
    z-index: 1;
    overflow: visible;
}

.auth-header .game-logo {
    width: 140px;
    height: auto;
    filter: 
        drop-shadow(0 8px 24px rgba(0, 0, 0, 0.5))
        drop-shadow(0 3px 10px rgba(0, 0, 0, 0.3))
        drop-shadow(0 0 40px rgba(69, 123, 157, 0.6))
        drop-shadow(0 0 80px rgba(69, 123, 157, 0.3));
    animation: logoHeroGlow 4s ease-in-out infinite;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.auth-header .game-logo:hover {
    transform: scale(1.15) translateY(-6px);
    filter: 
        drop-shadow(0 10px 30px rgba(0, 0, 0, 0.6))
        drop-shadow(0 5px 15px rgba(0, 0, 0, 0.4))
        drop-shadow(0 0 50px rgba(69, 123, 157, 0.8))
        drop-shadow(0 0 100px rgba(69, 123, 157, 0.4));
}

@keyframes logoHeroGlow {
    0%, 100% { 
        filter: 
            drop-shadow(0 8px 24px rgba(0, 0, 0, 0.5))
            drop-shadow(0 3px 10px rgba(0, 0, 0, 0.3))
            drop-shadow(0 0 40px rgba(69, 123, 157, 0.6))
            drop-shadow(0 0 80px rgba(69, 123, 157, 0.3));
    }
    50% { 
        filter: 
            drop-shadow(0 10px 28px rgba(0, 0, 0, 0.55))
            drop-shadow(0 5px 14px rgba(0, 0, 0, 0.35))
            drop-shadow(0 0 60px rgba(69, 123, 157, 0.8))
            drop-shadow(0 0 120px rgba(69, 123, 157, 0.4));
    }
}

@keyframes logoHeroEntrance {
    0% {
        opacity: 0;
        transform: translateY(-40px) scale(0.7);
    }
    60% {
        transform: translateY(5px) scale(1.05);
    }
    100% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* Title "BATTLESHIP GAME" - Font Bungee (Gaming Bold) */
.auth-header h1 {
    font-family: 'Bungee', 'Black Ops One', 'Impact', cursive, sans-serif;
    font-size: 36px;
    font-weight: 400;
    margin: 0;
    letter-spacing: 2px;
    text-transform: uppercase;
    text-shadow: 
        0 3px 10px rgba(0, 0, 0, 0.5),
        0 5px 20px rgba(0, 0, 0, 0.3),
        0 0 40px rgba(69, 123, 157, 0.4);
    position: relative;
    z-index: 1;
    color: #ffffff;
    line-height: 1.3;
}

/* Subtitle - Be Vietnam Pro cho tiếng Việt */
.subtitle {
    font-family: 'Be Vietnam Pro', 'Inter', 'Roboto', sans-serif;
    font-size: 13.5px;
    margin-top: 12px;
    opacity: 0.94;
    letter-spacing: 0.3px;
    font-weight: 500;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.25);
    color: rgba(255, 255, 255, 0.96);
}

/* ========================================
   TAB NAVIGATION - PREMIUM SEGMENTED CONTROL
   ======================================== */

.auth-tabs {
    padding: 0;
}

/* Tab Navigation - Premium Pill Container */
.tab-nav {
    display: flex;
    position: relative;
    background: linear-gradient(135deg, rgba(69, 123, 157, 0.15) 0%, rgba(29, 53, 87, 0.12) 100%);
    backdrop-filter: blur(10px);
    padding: 4px;
    border-radius: 14px;
    margin: 18px 20px 0;
    gap: 3px;
    box-shadow: 
        inset 0 1px 3px rgba(0, 0, 0, 0.1),
        0 1px 0 rgba(255, 255, 255, 0.3);
}

.tab-btn {
    flex: 1;
    padding: 11px 14px;
    background: transparent;
    border: none;
    color: #6c757d;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.22s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    z-index: 2;
    font-family: 'Be Vietnam Pro', sans-serif;
    border-radius: 10px;
    white-space: nowrap;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.tab-btn:hover:not(.active) {
    color: #495057;
    background: rgba(255, 255, 255, 0.35);
    transform: translateY(-1px);
}

.tab-btn.active {
    color: #1d3557;
    font-weight: 700;
    text-shadow: 0 0.5px 0 rgba(255, 255, 255, 0.8);
}

/* Premium Pill Indicator with Gradient */
.tab-indicator {
    position: absolute;
    top: 4px;
    left: 4px;
    height: calc(100% - 8px);
    width: calc(33.333% - 6px);
    background: linear-gradient(135deg, 
        rgba(255, 255, 255, 0.98) 0%, 
        rgba(255, 255, 255, 0.95) 50%,
        rgba(232, 244, 248, 0.92) 100%);
    transition: all 0.26s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 10px;
    box-shadow: 
        0 3px 12px rgba(29, 53, 87, 0.2),
        0 1px 4px rgba(0, 0, 0, 0.12),
        inset 0 1px 0 rgba(255, 255, 255, 1),
        inset 0 -1px 0 rgba(69, 123, 157, 0.1);
    z-index: 1;
    border: 1px solid rgba(69, 123, 157, 0.15);
}

.tab-indicator[data-active="login"] {
    transform: translateX(0);
}

.tab-indicator[data-active="register"] {
    transform: translateX(calc(100% + 7px));
}

.tab-indicator[data-active="guest"] {
    transform: translateX(calc(200% + 14px));
}

/* Tab Content */
.tab-content-wrapper {
    overflow: hidden;
    position: relative;
}

.tab-panels {
    display: flex;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    width: 300%;
}

.tab-panels[data-current-tab="login"] {
    transform: translateX(0);
}

.tab-panels[data-current-tab="register"] {
    transform: translateX(-33.333%);
}

.tab-panels[data-current-tab="guest"] {
    transform: translateX(-66.666%);
}

.tab-panel {
    flex: 0 0 33.333%;
    padding: 26px 24px 20px;
    box-sizing: border-box;
    opacity: 0;
    transition: opacity 0.4s ease;
}

.tab-panel.active {
    opacity: 1;
}

/* ========================================
   FORM STYLES - COMPACT
   ======================================== */

.form-group {
    margin-bottom: 18px;
}

.form-group:last-of-type {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 7px;
    color: #1d3557;
    font-weight: 600;
    font-size: 13px;
    font-family: 'Be Vietnam Pro', sans-serif;
    letter-spacing: 0.2px;
}

/* Input Wrapper with Icons */
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 14px;
    font-size: 17px;
    opacity: 0.6;
    pointer-events: none;
    z-index: 2;
    transition: all 0.24s ease;
    display: flex;
    align-items: center;
    height: 100%;
}

.input-wrapper input {
    width: 100%;
    padding: 12px 14px 12px 44px;
    border: 1.5px solid rgba(69, 123, 157, 0.25);
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.24s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: 'Be Vietnam Pro', sans-serif;
    background: rgba(255, 255, 255, 0.85);
    color: #1d3557;
}

.input-wrapper input::placeholder {
    color: rgba(29, 53, 87, 0.45);
    font-size: 13px;
}

.input-wrapper input:focus {
    outline: none;
    border-color: #457b9d;
    border-width: 2px;
    padding: 11px 13px 11px 43px;
    box-shadow: 
        0 0 0 3px rgba(69, 123, 157, 0.12),
        0 2px 8px rgba(69, 123, 157, 0.15);
    background: rgba(255, 255, 255, 0.95);
}

.input-wrapper input:focus + .input-icon,
.input-wrapper:focus-within .input-icon {
    opacity: 1;
    transform: scale(1.1);
}

/* Password Toggle Button */
.toggle-password {
    position: absolute;
    right: 10px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    font-size: 17px;
    opacity: 0.55;
    transition: all 0.24s ease;
    z-index: 2;
    line-height: 1;
    display: flex;
    align-items: center;
}

.toggle-password:hover {
    opacity: 1;
    transform: scale(1.12);
}

.toggle-password .eye-icon {
    display: block;
}

/* Fallback for inputs without wrappers */
.form-group input:not(.input-wrapper input) {
    width: 100%;
    padding: 12px 14px;
    border: 1.5px solid rgba(69, 123, 157, 0.25);
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.24s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: 'Be Vietnam Pro', sans-serif;
    background: rgba(255, 255, 255, 0.85);
    color: #1d3557;
}

.form-group input:not(.input-wrapper input):focus {
    outline: none;
    border-color: #457b9d;
    border-width: 2px;
    padding: 11px 13px;
    box-shadow: 
        0 0 0 3px rgba(69, 123, 157, 0.12),
        0 2px 8px rgba(69, 123, 157, 0.15);
    background: rgba(255, 255, 255, 0.95);
}

/* ========================================
   BUTTONS - PREMIUM CTA WITH NAVY→CYAN GRADIENT
   ======================================== */

.btn {
    width: 100%;
    padding: 14px 20px;
    border: none;
    border-radius: 11px;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.22s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: 'Be Vietnam Pro', sans-serif;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, #1d3557 0%, #457b9d 50%, #5fa8c5 100%);
    color: white;
    box-shadow: 
        0 4px 16px rgba(29, 53, 87, 0.4),
        0 2px 8px rgba(69, 123, 157, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(95, 168, 197, 0.3);
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.25) 0%, transparent 70%);
    transform: translate(-50%, -50%);
    transition: width 0.5s ease-out, height 0.5s ease-out;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 
        0 6px 24px rgba(29, 53, 87, 0.5),
        0 3px 12px rgba(69, 123, 157, 0.4),
        0 0 20px rgba(95, 168, 197, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
    background: linear-gradient(135deg, #1d3557 0%, #457b9d 40%, #6bc1e0 100%);
    border-color: rgba(107, 193, 224, 0.5);
}

.btn-primary:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary:active {
    transform: translateY(0px);
    box-shadow: 
        0 2px 10px rgba(29, 53, 87, 0.45),
        0 1px 5px rgba(69, 123, 157, 0.35),
        inset 0 1px 3px rgba(0, 0, 0, 0.2);
}

.btn-primary:focus {
    outline: none;
    box-shadow: 
        0 4px 16px rgba(29, 53, 87, 0.4),
        0 2px 8px rgba(69, 123, 157, 0.3),
        0 0 0 4px rgba(95, 168, 197, 0.4);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* Secondary Buttons */
.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-success:hover {
    background: #218838;
    transform: translateY(-2px);
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
    transform: translateY(-2px);
}

.btn-admin {
    background: #9C27B0;
    color: white;
}

.btn-admin:hover {
    background: #7B1FA2;
    transform: translateY(-2px);
}

.btn-small {
    padding: 10px 20px;
    font-size: 14px;
}

/* ========================================
   GUEST PANEL - PREMIUM WITH STYLED ANCHOR
   ======================================== */

.guest-panel-content {
    text-align: center;
}

.guest-icon {
    font-size: 64px;
    margin-bottom: 16px;
    animation: anchorFloat 2.5s ease-in-out infinite;
    filter: 
        drop-shadow(0 4px 12px rgba(69, 123, 157, 0.5))
        drop-shadow(0 0 20px rgba(69, 123, 157, 0.3));
    color: #457b9d;
    display: inline-block;
    text-shadow: 
        0 2px 4px rgba(0, 0, 0, 0.2),
        0 0 10px rgba(69, 123, 157, 0.4);
}

@keyframes anchorFloat {
    0%, 100% { 
        transform: translateY(0px) rotate(0deg);
        filter: 
            drop-shadow(0 4px 12px rgba(69, 123, 157, 0.5))
            drop-shadow(0 0 20px rgba(69, 123, 157, 0.3));
    }
    25% { 
        transform: translateY(-6px) rotate(-3deg);
    }
    50% {
        transform: translateY(-8px) rotate(0deg);
        filter: 
            drop-shadow(0 6px 16px rgba(69, 123, 157, 0.6))
            drop-shadow(0 0 30px rgba(69, 123, 157, 0.5));
    }
    75% { 
        transform: translateY(-6px) rotate(3deg);
    }
}

.guest-panel-content h3 {
    font-size: 22px;
    color: #1d3557;
    margin-bottom: 8px;
    font-weight: 700;
    font-family: 'Be Vietnam Pro', sans-serif;
    letter-spacing: 0.3px;
}

.guest-description {
    color: #457b9d;
    margin-bottom: 24px;
    font-size: 14px;
    font-weight: 500;
}

.guest-panel-content .form-group {
    text-align: left;
}

/* ========================================
   ERROR & SUCCESS MESSAGES - COMPACT
   ======================================== */

.error-message {
    color: #dc3545;
    font-size: 13px;
    margin-top: 12px;
    padding: 10px 14px;
    border-radius: 8px;
    background: rgba(220, 53, 69, 0.1);
    border-left: 3px solid #dc3545;
    display: none;
    animation: shake 0.35s ease;
    font-weight: 500;
    line-height: 1.4;
}

.error-message.show {
    display: block;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-8px); }
    75% { transform: translateX(8px); }
}

.success-message {
    color: #28a745;
    font-size: 13px;
    margin-top: 12px;
    padding: 10px 14px;
    border-radius: 8px;
    background: rgba(40, 167, 69, 0.1);
    border-left: 3px solid #28a745;
    font-weight: 500;
    line-height: 1.4;
}

/* ========================================
   UTILITY CLASSES
   ======================================== */

.switch-form {
    text-align: center;
    margin-top: 20px;
    color: #6c757d;
    font-size: 14px;
}

.switch-form a {
    color: #457b9d;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.switch-form a:hover {
    color: #1d3557;
    text-decoration: underline;
}

.separator {
    display: flex;
    align-items: center;
    margin: 20px 0;
    color: #6c757d;
}

.separator::before,
.separator::after {
    content: '';
    flex: 1;
    height: 1px;
    background: rgba(69, 123, 157, 0.2);
}

.separator span {
    padding: 0 15px;
    font-size: 13px;
    font-weight: 500;
}

.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.6s linear infinite;
    margin-left: 10px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ========================================
   RESPONSIVE DESIGN - LOGO HERO SIZES
   ======================================== */

@media (max-width: 768px) {
    .container {
        padding: 30px 20px;
    }

    .auth-header {
        padding: 38px 20px 26px;
    }

    /* Logo Hero - Tablet - Phóng to */
    .auth-header .game-logo {
        width: 120px;
    }

    .auth-header h1 {
        font-size: 32px;
        letter-spacing: 0.6px;
    }

    .subtitle {
        font-size: 12.5px;
        letter-spacing: 0.2px;
    }

    .tab-nav {
        margin: 16px 18px 0;
    }

    .tab-btn {
        font-size: 12px;
        padding: 10px 10px;
        letter-spacing: 0.2px;
    }

    .tab-panel {
        padding: 22px 18px 18px;
    }
}

@media (max-width: 500px) {
    .container {
        padding: 24px 16px;
    }

    .auth-box {
        border-radius: 18px;
    }

    .auth-header {
        padding: 32px 18px 24px;
    }

    /* Logo Hero - Mobile */
    .auth-header .game-logo {
        width: 88px;
    }

    .auth-header h1 {
        font-size: 28px;
        letter-spacing: 0.5px;
    }

    .subtitle {
        font-size: 12px;
        letter-spacing: 0.2px;
    }

    .tab-nav {
        margin: 14px 16px 0;
        padding: 3px;
    }

    .tab-btn {
        font-size: 11px;
        padding: 9px 6px;
    }

    .tab-panel {
        padding: 20px 16px 16px;
    }

    .form-group {
        margin-bottom: 16px;
    }

    .guest-icon {
        font-size: 54px;
        margin-bottom: 12px;
    }

    .guest-panel-content h3 {
        font-size: 20px;
    }

    .guest-description {
        margin-bottom: 20px;
        font-size: 13px;
    }

    .btn {
        padding: 13px 18px;
        font-size: 14px;
    }
}

/* Extra small devices (360px and below) */
@media (max-width: 360px) {
    .container {
        padding: 20px 12px;
    }

    .auth-box {
        max-width: 100%;
    }

    .auth-header {
        padding: 28px 16px 22px;
    }

    /* Logo Hero - Extra Small */
    .auth-header .game-logo {
        width: 80px;
    }

    .auth-header h1 {
        font-size: 24px;
        letter-spacing: 0.4px;
    }

    .subtitle {
        font-size: 11px;
        margin-top: 8px;
        letter-spacing: 0.1px;
    }

    .tab-nav {
        margin: 12px 14px 0;
        padding: 3px;
        gap: 2px;
    }

    .tab-btn {
        font-size: 10px;
        padding: 8px 4px;
        letter-spacing: 0.1px;
    }

    .tab-indicator {
        width: calc(33.333% - 5px);
    }

    .tab-indicator[data-active="register"] {
        transform: translateX(calc(100% + 5px));
    }

    .tab-indicator[data-active="guest"] {
        transform: translateX(calc(200% + 10px));
    }

    .tab-panel {
        padding: 18px 14px 14px;
    }

    .form-group label {
        font-size: 12px;
    }

    .input-wrapper input {
        font-size: 13px;
        padding: 11px 12px 11px 40px;
    }

    .input-icon {
        font-size: 15px;
        left: 12px;
    }

    .btn {
        padding: 12px 16px;
        font-size: 13px;
    }

    .guest-icon {
        font-size: 48px;
    }

    .guest-panel-content h3 {
        font-size: 18px;
    }
}

/* ========================================
   HEIGHT-BASED RESPONSIVE (Small Laptops)
   ======================================== */

/* Medium height screens (768px - 900px) - 13-14 inch laptops */
@media (max-height: 900px) {
    .container {
        padding: 20px 20px;
        justify-content: flex-start;
    }

    .auth-box {
        margin: 20px 0;
        max-height: 95vh;
        overflow-y: auto;
    }

    .auth-header {
        padding: 30px 20px 20px;
    }

    .auth-header .game-logo {
        width: 100px;
    }

    .auth-header h1 {
        font-size: 30px;
    }

    .subtitle {
        font-size: 12.5px;
    }

    .tab-panel {
        padding: 20px 20px 16px;
    }

    .form-group {
        margin-bottom: 14px;
    }

    .guest-icon {
        font-size: 52px;
        margin-bottom: 10px;
    }
}

/* Small height screens (600px - 768px) - 11-12 inch laptops */
@media (max-height: 768px) {
    body {
        overflow-y: auto;
    }

    .container {
        padding: 15px 20px;
        justify-content: flex-start;
        min-height: auto;
    }

    .auth-box {
        margin: 15px 0;
        max-height: none;
        overflow-y: visible;
    }

    .auth-header {
        padding: 24px 18px 18px;
    }

    .auth-header .logo-container {
        margin-bottom: 16px;
    }

    .auth-header .game-logo {
        width: 80px;
    }

    .auth-header h1 {
        font-size: 26px;
        letter-spacing: 1px;
    }

    .subtitle {
        font-size: 12px;
        margin-top: 8px;
    }

    .tab-nav {
        margin: 14px 18px 0;
        padding: 3px;
    }

    .tab-btn {
        padding: 9px 10px;
        font-size: 12px;
    }

    .tab-panel {
        padding: 18px 18px 14px;
    }

    .form-group {
        margin-bottom: 12px;
    }

    .form-group:last-of-type {
        margin-bottom: 16px;
    }

    .form-group label {
        margin-bottom: 6px;
        font-size: 12.5px;
    }

    .input-wrapper input {
        padding: 10px 12px 10px 40px;
        font-size: 13.5px;
    }

    .input-wrapper input:focus {
        padding: 9px 11px 9px 39px;
    }

    .input-icon {
        font-size: 16px;
        left: 12px;
    }

    .toggle-password {
        font-size: 16px;
    }

    .btn {
        padding: 12px 18px;
        font-size: 14px;
    }

    .guest-icon {
        font-size: 48px;
        margin-bottom: 10px;
    }

    .guest-panel-content h3 {
        font-size: 20px;
        margin-bottom: 6px;
    }

    .guest-description {
        margin-bottom: 18px;
        font-size: 13px;
    }

    .error-message,
    .success-message {
        margin-top: 10px;
        padding: 9px 12px;
        font-size: 12.5px;
    }
}

/* Extra small height screens (< 600px) - Netbooks/Small laptops */
@media (max-height: 600px) {
    .container {
        padding: 10px 16px;
    }

    .auth-box {
        margin: 10px 0;
        border-radius: 16px;
    }

    .auth-header {
        padding: 18px 16px 14px;
    }

    .auth-header .logo-container {
        margin-bottom: 12px;
    }

    .auth-header .game-logo {
        width: 65px;
    }

    .auth-header h1 {
        font-size: 22px;
        letter-spacing: 0.5px;
    }

    .subtitle {
        font-size: 11px;
        margin-top: 6px;
    }

    .tab-nav {
        margin: 12px 16px 0;
        padding: 3px;
    }

    .tab-btn {
        padding: 8px 8px;
        font-size: 11px;
    }

    .tab-panel {
        padding: 16px 16px 12px;
    }

    .form-group {
        margin-bottom: 10px;
    }

    .form-group:last-of-type {
        margin-bottom: 14px;
    }

    .form-group label {
        margin-bottom: 5px;
        font-size: 12px;
    }

    .input-wrapper input {
        padding: 9px 11px 9px 38px;
        font-size: 13px;
        border-radius: 8px;
    }

    .input-wrapper input:focus {
        padding: 8px 10px 8px 37px;
    }

    .input-icon {
        font-size: 15px;
        left: 11px;
    }

    .toggle-password {
        font-size: 15px;
        padding: 5px;
    }

    .btn {
        padding: 11px 16px;
        font-size: 13px;
        border-radius: 9px;
    }

    .guest-icon {
        font-size: 40px;
        margin-bottom: 8px;
    }

    .guest-panel-content h3 {
        font-size: 18px;
        margin-bottom: 5px;
    }

    .guest-description {
        margin-bottom: 16px;
        font-size: 12px;
    }

    .error-message,
    .success-message {
        margin-top: 8px;
        padding: 8px 11px;
        font-size: 12px;
    }

    .switch-form {
        margin-top: 16px;
        font-size: 13px;
    }

    .separator {
        margin: 16px 0;
    }
}

/* Combined: Small laptop (width + height) */
@media (max-width: 1366px) and (max-height: 768px) {
    .container {
        padding: 12px 18px;
    }

    .auth-box {
        max-width: 400px;
    }

    .tab-panel {
        padding: 16px 18px 14px;
    }
}

/* Combined: Very small screens (old netbooks) */
@media (max-width: 1024px) and (max-height: 600px) {
    .container {
        padding: 8px 14px;
    }

    .auth-box {
        max-width: 380px;
        margin: 8px 0;
    }

    .auth-header {
        padding: 16px 14px 12px;
    }

    .tab-panel {
        padding: 14px 14px 12px;
    }

    .form-group {
        margin-bottom: 9px;
    }
}

/* Landscape tablets with keyboard (iPad landscape) */
@media (max-width: 1024px) and (max-height: 768px) and (orientation: landscape) {
    .container {
        justify-content: flex-start;
        padding: 10px 20px;
    }

    .auth-box {
        margin: 10px auto;
    }

    .auth-header {
        padding: 20px 18px 16px;
    }

    .guest-icon {
        font-size: 44px;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .tab-nav {
        user-select: none;
        -webkit-user-select: none;
        -webkit-touch-callout: none;
    }
    
    .tab-panels {
        touch-action: pan-x;
    }

    .btn-primary:hover {
        transform: none;
    }

    .btn-primary:active {
        transform: scale(0.98);
    }
}

/* Smooth scrolling for small screens */
@media (max-height: 768px) {
    html {
        scroll-behavior: smooth;
    }

    body {
        -webkit-overflow-scrolling: touch;
    }

    .auth-box {
        /* Smooth internal scrolling if needed */
        -webkit-overflow-scrolling: touch;
    }
}


html, body{ height: 100%; }

body{
  overflow: hidden;      /* no page scrollbar gutter */
  overflow-x: hidden;
}

/* Always center the card */
.container{
  min-height: 100vh;
  min-height: 100svh;
  justify-content: center;
  overflow: hidden;
}

/* Do not let older media queries force card scrolling */
.auth-box{
  overflow: hidden !important;
  max-height: none !important;
}

/* Slider wrapper: height controlled by JS */
.tab-content-wrapper{
  overflow-x: hidden;
  overflow-y: hidden;
  transition: height .25s ease;
}

/* IMPORTANT: stop flex stretch that causes blank space */
.tab-panels{
  align-items: flex-start; /* each panel keeps its own natural height */
}

/* Safety: ensure panel doesn't stretch */
.tab-panel{
  align-self: flex-start;
}

/* Register-only internal scroll (Facebook-like) */
body.is-register .tab-panel.active{
  max-height: min(560px, calc(100svh - 320px));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  padding-right: 10px;
}

/* Hide scrollbar but keep scroll */
body.is-register .tab-panel.active{
  scrollbar-width: none;
  -ms-overflow-style: none;
}
body.is-register .tab-panel.active::-webkit-scrollbar{
  width: 0;
  height: 0;
}

/* Small laptop heights: tighter header so Register fits better */
@media (max-height: 768px){
  .container{ padding: 14px 18px; }
  .auth-header{ padding: 30px 20px 20px; }
  .auth-header .game-logo{ width: 100px; }
  .auth-header h1{ font-size: 30px; }
}

/* Very small heights fallback */
@media (max-height: 650px){
  body.is-register .tab-panel.active{
    max-height: calc(100svh - 260px);
  }
}