/* 
 * Student Login Page Stylesheet
 * Modern, Professional & Stylish Design
 * Skill Tech LMS
 */

:root {
    /* Primary Colors - Professional Education Theme */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #3b82f6;
    --primary-dark: #1e40af;
    
    /* Gradient Colors */
    --gradient-start: #2563eb;
    --gradient-middle: #7c3aed;
    --gradient-end: #ec4899;
    
    /* Background Colors */
    --bg-gradient-start: #1e3a8a;
    --bg-gradient-end: #581c87;
    
    /* Text Colors */
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-light: #64748b;
    --text-white: #ffffff;
    
    /* Border & Divider */
    --border-color: #e2e8f0;
    --border-focus: #2563eb;
    
    /* Shadow */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-primary: 0 10px 40px rgba(37, 99, 235, 0.2);
    
    /* Card Background */
    --card-bg: rgba(255, 255, 255, 0.98);
    --card-bg-dark: rgba(15, 23, 42, 0.95);
}

[data-theme="dark"] {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: #60a5fa;
    
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-light: #94a3b8;
    
    --border-color: #334155;
    --border-focus: #3b82f6;
    
    --card-bg: rgba(15, 23, 42, 0.95);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--bg-gradient-start) 0%, #4c1d95 50%, var(--bg-gradient-end) 100%);
    position: relative;
    overflow: hidden;
    padding: 20px;
}

/* Animated Background Elements */
body::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 20s ease-in-out infinite;
    z-index: 0;
}

body::after {
    content: '';
    position: absolute;
    bottom: -40%;
    left: -15%;
    width: 700px;
    height: 700px;
    background: radial-gradient(circle, rgba(236, 72, 153, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 25s ease-in-out infinite reverse;
    z-index: 0;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(30px, -30px) scale(1.05);
    }
    66% {
        transform: translate(-20px, 20px) scale(0.95);
    }
}

/* Additional Animated Orbs */
body {
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(59, 130, 246, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(236, 72, 153, 0.1) 0%, transparent 50%);
    background-attachment: fixed;
}

.login-container {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 460px;
    animation: fadeInScale 0.6s ease-out;
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.login-card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 40px 40px;
    box-shadow: var(--shadow-2xl), var(--shadow-primary);
    border: 1px solid rgba(255, 255, 255, 0.2);
    animation: slideUpFade 0.7s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

[data-theme="dark"] .login-card {
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.login-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-middle), var(--gradient-end));
    background-size: 200% 100%;
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0%, 100% {
        background-position: 0% 0%;
    }
    50% {
        background-position: 100% 0%;
    }
}

@keyframes slideUpFade {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-logo {
    width: 72px;
    height: 72px;
    margin: 0 auto 18px;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-middle) 50%, var(--gradient-end) 100%);
    border-radius: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    color: var(--text-white);
    box-shadow: 0 12px 32px rgba(37, 99, 235, 0.4), 0 0 0 4px rgba(255, 255, 255, 0.1);
    position: relative;
    animation: logoPulse 3s ease-in-out infinite;
}

@keyframes logoPulse {
    0%, 100% {
        box-shadow: 0 12px 32px rgba(37, 99, 235, 0.4), 0 0 0 4px rgba(255, 255, 255, 0.1);
    }
    50% {
        box-shadow: 0 12px 40px rgba(37, 99, 235, 0.6), 0 0 0 6px rgba(255, 255, 255, 0.15);
    }
}

.login-title {
    font-size: 28px;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 6px;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, var(--text-primary), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

[data-theme="dark"] .login-title {
    background: linear-gradient(135deg, var(--text-primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-subtitle {
    font-size: 15px;
    color: var(--text-secondary);
    font-weight: 500;
    letter-spacing: 0.2px;
}

/* Alert Styles */
.alert {
    padding: 14px 18px;
    border-radius: 12px;
    margin-bottom: 24px;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 12px;
    animation: slideDown 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    font-weight: 500;
    backdrop-filter: blur(10px);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.alert-error {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.15) 0%, rgba(220, 38, 38, 0.1) 100%);
    color: #dc2626;
    border: 1px solid rgba(239, 68, 68, 0.3);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.15);
}

.alert-success {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.15) 0%, rgba(5, 150, 105, 0.1) 100%);
    color: #059669;
    border: 1px solid rgba(16, 185, 129, 0.3);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.15);
}

.alert i {
    font-size: 18px;
}

/* Form Styles */
.form-group {
    margin-bottom: 20px;
    position: relative;
}

.form-label {
    display: block;
    margin-bottom: 10px;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 14px;
    letter-spacing: 0.2px;
}

.form-input-wrapper {
    position: relative;
}

.form-input-icon {
    position: absolute;
    left: 18px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-light);
    font-size: 18px;
    transition: all 0.3s ease;
    z-index: 1;
}

.form-group:focus-within .form-input-icon {
    color: var(--primary-color);
    transform: translateY(-50%) scale(1.1);
}

.password-toggle {
    position: absolute;
    right: 18px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-light);
    font-size: 18px;
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 1;
    border-radius: 6px;
}

.password-toggle:hover {
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
}

.password-toggle:active {
    transform: translateY(-50%) scale(0.95);
}

.form-group:focus-within .password-toggle {
    color: var(--text-secondary);
}

.form-control {
    width: 100%;
    padding: 16px 52px 16px 52px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 15px;
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.8);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-weight: 500;
    letter-spacing: 0.2px;
}

#password {
    padding-right: 56px;
}

[data-theme="dark"] .form-control {
    background: rgba(30, 41, 59, 0.6);
    border-color: var(--border-color);
}

.form-control::placeholder {
    color: var(--text-light);
    font-weight: 400;
}

.form-control:hover {
    border-color: var(--primary-light);
    background: rgba(255, 255, 255, 0.95);
}

[data-theme="dark"] .form-control:hover {
    background: rgba(30, 41, 59, 0.8);
}

.form-control:focus {
    outline: none;
    border-color: var(--border-focus);
    background: rgba(255, 255, 255, 1);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1), 0 4px 12px rgba(37, 99, 235, 0.15);
    transform: translateY(-1px);
}

[data-theme="dark"] .form-control:focus {
    background: rgba(30, 41, 59, 0.9);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.15), 0 4px 12px rgba(59, 130, 246, 0.2);
}

/* Form Options */
.form-options {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    margin-bottom: 24px;
    font-size: 14px;
}

.remember-me {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 500;
    transition: color 0.2s ease;
    user-select: none;
}

.remember-me:hover {
    color: var(--text-primary);
}

.remember-me input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--primary-color);
    border-radius: 5px;
    transition: transform 0.2s ease;
}

.remember-me input[type="checkbox"]:hover {
    transform: scale(1.1);
}

/* Login Button */
.btn-login {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-middle) 50%, var(--gradient-end) 100%);
    background-size: 200% 100%;
    color: var(--text-white);
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.35), 0 0 0 1px rgba(255, 255, 255, 0.1) inset;
    letter-spacing: 0.3px;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    font-size: 15px;
    letter-spacing: 0.5px;
}

.btn-login::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(37, 99, 235, 0.45), 0 0 0 1px rgba(255, 255, 255, 0.15) inset;
    background-position: 100% 0%;
}

.btn-login:hover::before {
    left: 100%;
}

.btn-login:active {
    transform: translateY(0);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35);
}

.btn-login:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    background-position: 0% 0%;
}

.btn-login i {
    margin-right: 10px;
    font-size: 16px;
}

/* Footer */
.login-footer {
    text-align: center;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
    font-size: 13px;
    color: var(--text-light);
    font-weight: 500;
}

/* Theme Toggle */
.theme-toggle-wrapper {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 100;
}

.theme-toggle {
    width: 50px;
    height: 50px;
    border-radius: 14px;
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    color: var(--text-primary);
}

[data-theme="dark"] .theme-toggle {
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.theme-toggle:hover {
    transform: translateY(-2px) rotate(15deg);
    box-shadow: var(--shadow-xl);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: var(--text-white);
}

.theme-toggle:active {
    transform: translateY(0) rotate(0deg);
}

/* Responsive Design */
@media (max-width: 640px) {
    body {
        padding: 16px;
    }
    
    .login-card {
        padding: 36px 32px;
        border-radius: 20px;
    }
    
    .login-logo {
        width: 68px;
        height: 68px;
        font-size: 34px;
        margin-bottom: 16px;
    }
    
    .login-title {
        font-size: 26px;
    }
    
    .login-subtitle {
        font-size: 14px;
    }
    
    .form-group {
        margin-bottom: 18px;
    }
    
    .form-control {
        padding: 14px 16px 14px 48px;
        font-size: 14px;
    }
    
    #password {
        padding-right: 52px;
    }
    
    .password-toggle {
        right: 14px;
        font-size: 16px;
    }
    
    .btn-login {
        padding: 14px;
        font-size: 14px;
    }
    
    .theme-toggle-wrapper {
        top: 16px;
        right: 16px;
    }
    
    .theme-toggle {
        width: 44px;
        height: 44px;
        font-size: 20px;
        border-radius: 12px;
    }
}

@media (max-width: 480px) {
    .login-card {
        padding: 36px 24px;
    }
    
    .login-header {
        margin-bottom: 28px;
    }
    
    .login-title {
        font-size: 24px;
    }
    
    .alert {
        padding: 14px 16px;
        font-size: 13px;
        margin-bottom: 20px;
    }
    
    .form-options {
        margin-bottom: 20px;
    }
    
    .login-footer {
        margin-top: 20px;
        padding-top: 20px;
    }
}

/* Loading State */
.btn-login.loading {
    pointer-events: none;
    opacity: 0.8;
}

.btn-login.loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    top: 50%;
    left: 50%;
    margin-left: -10px;
    margin-top: -10px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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