/* === Variables === */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-darker: #1a42b1;
    --color-text-dark: #1e293b;
    --color-text-medium: #334155;
    --color-text-light: #64748b;
    --color-background-light: #f9fafb;
    --color-background-medium: #f1f5f9;
    --color-background-strong: #e2e8f0;
    --color-white: #ffffff;
    --color-border-light: #e2e8f0;
    --color-border-medium: #cbd5e1;
    --color-border-dark: #cbd5e1;
    --flash-success-bg: #d1fae5;
    --flash-success-text: #065f46;
    --flash-success-border: #10b981;
    --flash-error-bg: #fee2e2;
    --flash-error-text: #991b1b;
    --flash-error-border: #ef4444;
    --flash-info-bg: #e0f2fe;
    --flash-info-text: #1e40af;
    --flash-info-border: #3b82f6;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 0.75rem;
    --spacing-lg: 1rem;
    --spacing-xl: 1.5rem;
    --spacing-xxl: 2rem;
    --spacing-xxxl: 3rem;
    --font-size-base: 14px;
    --font-size-sm: 0.875rem;
    --font-size-md: 0.95rem;
    --font-size-lg: 1.1rem;
    --font-size-xl: 1.2rem;
    --font-size-h1: 28px;
    --font-size-h2: 24px;
    --border-radius-sm: 4px;
    --border-radius-md: 6px;
    --border-radius-lg: 8px;
    --border-radius-xl: 10px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.12);
    --shadow-input-inset: inset 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.2);
    --transition-fast: 0.1s ease-in-out;
    --transition-normal: 0.2s ease-in-out;
    --transition-slow: 0.3s ease-in-out;
}

/* === Base === */
html {
    color-scheme: light;
}

body {
    font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    color: var(--color-text-medium);
    background:
        radial-gradient(circle at top right, #eef4ff 0, transparent 35%),
        radial-gradient(circle at bottom left, #eff6ff 0, transparent 30%),
        var(--color-background-light);
    font-size: var(--font-size-base);
    line-height: 1.5;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-normal);
}

a:hover {
    color: var(--color-primary-dark);
}

h1,
h2,
h3 {
    margin: 0 0 var(--spacing-sm);
    color: var(--color-text-dark);
    font-weight: 700;
    letter-spacing: 0.01em;
}

.material-icons {
    vertical-align: middle;
}

.main-content {
    flex: 1 1 auto;
    width: 100%;
    max-width: 1120px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    box-sizing: border-box;
}

/* === Navbar === */
.app-navbar {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg) var(--spacing-xxl);
    background: rgba(255, 255, 255, 0.88);
    border-bottom: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(8px);
}

.nav-title,
.nav-user {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-title a,
.nav-logout {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-dark);
    font-weight: 600;
}

.brand-icon,
.nav-logout .material-icons {
    color: var(--color-primary);
}

/* === Flash Messages === */
.flash-messages {
    list-style: none;
    padding: 0;
    margin: 0 0 var(--spacing-xl);
}

.flash-messages li {
    padding: var(--spacing-md) var(--spacing-lg);
    border: 1px solid;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-md);
    font-weight: 600;
}

.flash-messages .success {
    background: var(--flash-success-bg);
    color: var(--flash-success-text);
    border-color: var(--flash-success-border);
}

.flash-messages .error,
.flash-messages .danger {
    background: var(--flash-error-bg);
    color: var(--flash-error-text);
    border-color: var(--flash-error-border);
}

.flash-messages .info {
    background: var(--flash-info-bg);
    color: var(--flash-info-text);
    border-color: var(--flash-info-border);
}

/* === Login === */
.login-page-main {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: clamp(3rem, 8vh, 6rem);
    padding-bottom: var(--spacing-xxxl);
}

.login-container {
    width: min(460px, 100%);
    padding: var(--spacing-xxxl);
    border: 1px solid rgba(203, 213, 225, 0.8);
    border-radius: 22px;
    background: rgba(255, 255, 255, 0.92);
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.login-container h2 {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    margin-bottom: var(--spacing-xl);
    font-size: 1.75rem;
}

.login-container h2 .material-icons {
    color: var(--color-primary);
}

.login-copy {
    margin: 0 0 var(--spacing-xl);
    color: var(--color-text-light);
    font-size: var(--font-size-md);
}

.auth-signin-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 52px;
    padding: 0.85rem 1.25rem;
    border: none;
    border-radius: var(--border-radius-xl);
    background: linear-gradient(180deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: var(--color-white);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-normal);
}

.auth-signin-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    filter: brightness(1.03);
}

.auth-signin-button:active {
    transform: translateY(0);
    background: var(--color-primary-darker);
}

/* === Bucket Page === */
.bucket-container {
    background: rgba(255, 255, 255, 0.92);
    border: 1px solid var(--color-border-light);
    border-radius: 18px;
    box-shadow: var(--shadow-md);
    padding: clamp(1.25rem, 2vw, 2rem);
}

.bucket-container h2 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
}

.bucket-container h2 .material-icons {
    color: var(--color-primary);
}

.upload-form {
    margin-bottom: var(--spacing-xl);
}

.upload-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    padding: var(--spacing-lg);
    border: 1px dashed var(--color-border-medium);
    border-radius: var(--border-radius-lg);
    background: var(--color-background-medium);
}

.file-input {
    flex: 1 1 260px;
    min-width: 0;
    padding: 0.7rem 0.85rem;
    border: 1px solid var(--color-border-medium);
    border-radius: var(--border-radius-md);
    background: var(--color-white);
    box-shadow: var(--shadow-input-inset);
}

.upload-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.8rem 1.2rem;
    border: none;
    border-radius: var(--border-radius-md);
    background: var(--color-primary);
    color: var(--color-white);
    font-weight: 700;
    cursor: pointer;
    transition: background-color var(--transition-normal), transform var(--transition-fast);
}

.upload-button:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
}

.table-wrapper {
    overflow-x: auto;
}

.file-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    overflow: hidden;
    border: 1px solid var(--color-border-light);
    border-radius: var(--border-radius-lg);
    background: var(--color-white);
    box-shadow: var(--shadow-sm);
}

.file-table th,
.file-table td {
    padding: 0.95rem 1rem;
    text-align: left;
}

.file-table th {
    background: var(--color-background-medium);
    color: var(--color-text-dark);
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    border-bottom: 1px solid var(--color-border-dark);
}

.file-table tbody tr:nth-child(even) td {
    background: #fcfdff;
}

.file-table tbody tr:hover td {
    background: #f0f7ff;
}

.file-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.file-actions a {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-weight: 600;
}

.file-actions a.delete {
    color: #dc2626;
}

.file-actions a.delete:hover {
    color: #b91c1c;
}

.empty-state {
    margin: 0;
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    background: var(--color-background-medium);
    color: var(--color-text-light);
    text-align: center;
}

/* === Focus === */
.auth-signin-button:focus-visible,
.upload-button:focus-visible,
.file-input:focus-visible,
a:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    box-shadow: var(--shadow-focus-ring);
}

/* === Footer === */
.app-footer {
    margin-top: auto;
    padding: var(--spacing-xl) var(--spacing-xxl);
    text-align: center;
    color: var(--color-text-light);
    font-size: 0.9rem;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-primary: #60a5fa;
        --color-primary-dark: #3b82f6;
        --color-primary-darker: #2563eb;
        --color-text-dark: #e5eefb;
        --color-text-medium: #cbd5e1;
        --color-text-light: #94a3b8;
        --color-background-light: #08111f;
        --color-background-medium: #0f172a;
        --color-background-strong: #1e293b;
        --color-white: #111c2f;
        --color-border-light: #243247;
        --color-border-medium: #334155;
        --color-border-dark: #334155;
        --flash-success-bg: rgba(6, 95, 70, 0.25);
        --flash-success-text: #a7f3d0;
        --flash-success-border: #34d399;
        --flash-error-bg: rgba(153, 27, 27, 0.25);
        --flash-error-text: #fecaca;
        --flash-error-border: #f87171;
        --flash-info-bg: rgba(30, 64, 175, 0.25);
        --flash-info-text: #bfdbfe;
        --flash-info-border: #60a5fa;
        --shadow-sm: 0 4px 14px rgba(2, 6, 23, 0.35);
        --shadow-md: 0 16px 36px rgba(2, 6, 23, 0.4);
        --shadow-lg: 0 24px 56px rgba(2, 6, 23, 0.5);
        --shadow-input-inset: inset 0 1px 3px rgba(2, 6, 23, 0.45);
        --shadow-focus-ring: 0 0 0 3px rgba(96, 165, 250, 0.25);
    }

    html {
        color-scheme: dark;
    }

    body {
        background:
            radial-gradient(circle at top right, rgba(37, 99, 235, 0.16) 0, transparent 35%),
            radial-gradient(circle at bottom left, rgba(14, 165, 233, 0.14) 0, transparent 30%),
            linear-gradient(180deg, #08111f 0%, #0b1220 100%);
    }

    .app-navbar {
        background: rgba(8, 17, 31, 0.82);
    }

    .login-container,
    .bucket-container {
        background: rgba(15, 23, 42, 0.86);
    }

    .file-table tbody tr:nth-child(even) td {
        background: #101b30;
    }

    .file-table tbody tr:hover td {
        background: #15233b;
    }
}

/* === Responsive === */
@media (max-width: 900px) {
    .app-navbar {
        padding: var(--spacing-md) var(--spacing-lg);
    }

    .main-content {
        padding: var(--spacing-lg);
    }

    .login-container {
        padding: var(--spacing-xxl);
    }
}

@media (max-width: 640px) {
    .upload-row {
        align-items: stretch;
    }

    .upload-button,
    .auth-signin-button {
        width: 100%;
        justify-content: center;
    }

    .file-actions {
        gap: var(--spacing-sm);
    }
}